The present invention relates to cache management, and more particularly to determining whether a response to a data request may be retrieved from a cache or retrieved from another resource. Serving a data request from a cache instead of from an other resource can provide improved computer system efficiencies. For example, a central processing unit (CPU) cache is a cache used by the CPU of a computer to reduce the average time to access data from memory, wherein the CPU cache is a smaller, faster memory having a lower retrieval latency than a main memory of the computer, and wherein it is desirable to manage the CPU to cache copies of data frequently used rather than use slower main memory locations for said data. In network computer applications, a cache device or server may be provided to network users to supply lower retrieval latencies, reduce service provider requests and provide other improved system efficiencies with respect to requests served by cache data compared to requests that require service by other network resources, for example by another service provider server or memory device in communication with the network.